To each nation its own preventive strategy: that could be the motto drawn from the evolution of the public health response to contagious disease during the century from the first European cholera epidemics to the cusp of the antibiotical era. Why? Given that, in epidemiological and biological terms, the problem faced by each country has been much the same, why have they responded in markedly different ways? Is there an Archimedian point from which to pry an account of why nations have reacted with such different preventive tactics? That each has learned from epidemiological experience how better to counter the next onslaught is an observation on the historical evolution of public health so commonplace that, if anything, the historiographical temptation has been rather to caution against whiggish assumptions of an ever improving mastery of preventive techniques. What is at stake here, in contrast, are not such common learning experiences through which all nations eventually pass, arriving presumably at similar goals, but rather the different strategies they have adopted despite being faced with common problems.

Differences in scientific knowledge among nations that might have prompted varied responses cannot provide an explanation for at least two reasons. First, for the purposes of prevention, the state of the art in the nineteenth century was comparable, if not identical, across all.